We have four nieces that are having babies this fall! My sisters and I were talking about making receiving blankets. The ones that were made for our babies were square WOF, which was closer to 45" 30 years ago. The ones that I've seen in the store look so small.

Since flannel and quilting cottons seem to be ever narrower, I'm thinking about some other options. Dharma Trading Company has some heavy cotton gauze that is 50" wide after washing that I may order. It looks like the same gauze used in a popular brand of swaddling/receiving blanket. Since it only comes in white, I could bind or serge the edges in a color.

When my children were small 50 years ago, the flannel continued to shrink. Glad the quality of flannel is better now.
The 100% cotton was better quality back in the day, at least in my opinion, but the dyes seem better now

I do mine 42 x 42 for two reasons. If they want to swaddle, it is much easier if the blanket is larger and also, later on, they can lay it on the floor while the baby is doing tummy time and such. I love to put decorative stitching around the hems (all sides) and I use variegated thread. My daughter was very impressed, I didn't tell her that the machine did all the work...lol

I use to pieces of flannel square WOF. I round the corners and then envelope them together and top stitch around them. I use my edge foot to top stitch close to edge and this closes up the gap left to turn so no hand whip stitching it to close. My daughter loved this size.

I make my receiving blankets square (they are easier to wrap up the baby). I wash the fabric and make it square with the WOF -- so I would say only one from 1.5 yard.

That's exactly how I've always made mine, too. I personally liked square receiving blankets better so i just went with whatever size the WOF was. I also liked mine plenty big... nothing is worse than fighting a too-small blanket!